Alex Powell: Mitchell Santner or Colin de Grandhomme? Who should make cut for the Blackcaps' World Test Championship final XI

OPINION: With that pesky test series against England out of the way, Kiwi fans can now look forward to arguably the biggest game of cricket in our nation's history.

On Friday, June 18, the Blackcaps and India will begin their contest at Southampton's Ageas Bowl, with the winners to be crowned the ICC's inaugural world test champions.

But New Zealand's 1-0 series win over England - sealed with an eight-wicket victory at Birmingham's Edgbaston - has left selectors with serious questions and four days to answer them.

The biggest of those? Which of the 20-man squad currently in the Blackcaps camp should make up the playing XI to take on Virat Kohli's side.

While the batting line-up will likely pick itself - with captain Kane Williamson and wicketkeeper BJ Watling expected to slot back in at No.3 and No.6 respectively in place of Will Young and Tom Blundell - the real stumbling block could be the make-up of the bowling attack.

Since the start of 2020, the Blackcaps have conquered all before them with a simple strategy in terms of their seam attack, employing a left-arm swing bowler, a right-arm swing bowler, a left-arm bounce bowler and a right-arm bounce bowler.

For that reason, it would be shocking to see a seam attack built up of anything other than Trent Boult, Tim Southee, Neil Wagner and Kyle Jamieson.

But that would leave no room for Ajaz Patel, who took four wickets across both innings in Birmingham, with the Blackcaps unlikely to push Jamieson up to No.7 and weaken the batting as a result - even if it comes at the expense of a frontline spinner.

The captain-coach duo of Williamson and Gary Stead have made it clear in their words and their actions that they want a fifth bowling option, and the list of contenders to play at No.7 is not very long.

All-rounders Colin de Grandhomme and Daryl Mitchell are options for that final spot, both capable of batting in a lower-order role, but that would see New Zealand enter a final with no specialist spin option.

As dire as it may seem, the Blackcaps' only choice for who bats at No.7 could just be Mitchell Santner as a spinning all-rounder - provided he's overcome the finger injury that kept him out of the second test.

There's an old adage that it's better to have something and need it, than to need it and not have it. Santner fits that bill perfectly.

Spin won't be as decisive a factor as many would have you believe. After all, the World Test Championship final's being played in Southampton, not Chennai or Ahmedabad. 

The Blackcaps pace quartet are more than capable of taking 20 wickets over the course of a test match, but in case a few overs of spin are needed here and there to give the quicks a rest, Williamson is far more confident in Santner's ability with the ball than his own.

That's a very harsh call to make against de Grandhomme and Mitchell, both of whom are superior batsmen to Santner, but it would be an even bolder move to hand 21-year-old Rachin Ravindra a debut in the biggest game in New Zealand's history.

Is Santner the perfect solution? No, but at the very least it would give the Blackcaps the security of having that spinning option, with the ability to play their first-choice bowling attack.

Santner's bowling record will hardly fill India's batsmen with fear - 41 wickets in 24 tests at an average of just under 46 and a strike rate of nearly 99 balls - but his selection shouldn't come down to just statistics.

New Zealand's 20-man squad will be reduced to 15 on Tuesday (NZ time), with the five players to come home certain to give an indication to how the playing XI will look.

Ravindra, Jacob Duffy and Doug Bracewell didn't feature in either of the England tests, and will probably come home as three of the five.

Mitchell should be another omitted, hardly grabbing his chance in the second test by scoring six runs and not picking up a wicket.

That fifth and final player could be a case of 'thanks for coming' to Patel, with the Blackcaps unlikely to send home the spare batsman in Young or back-up wicketkeeper in Blundell.

It'd be a risky move considering Santner's finger, but if he was to be ruled out then de Grandhomme would definitely slot in as the all-rounder.

But barring a green-top in Southampton later this week, or a flare up of his spinning finger, Santner could just find himself as the final piece of the Blackcaps jigsaw.

Blackcaps (predicted XI): 1. Tom Latham, 2. Devon Conway, 3. Kane Williamson (c), 4. Ross Taylor, 5. Henry Nicholls, 6. BJ Watling (wk), 7. Mitchell Santner, 8. Kyle Jamieson, 9. Tim Southee, 10. Neil Wagner, 11. Trent Boult.